diff --git a/src/ast/simplifiers/elim_term_ite.h b/src/ast/simplifiers/elim_term_ite.h
index 6455db321..5b6ef38fa 100644
--- a/src/ast/simplifiers/elim_term_ite.h
+++ b/src/ast/simplifiers/elim_term_ite.h
@@ -15,7 +15,7 @@ Author:
 #pragma once
 
 #include "ast/simplifiers/dependent_expr_state.h"
-#include "ast/normal_forms/elim_term_ite.h""
+#include "ast/normal_forms/elim_term_ite.h"
 
 
 class elim_term_ite_simplifier : public dependent_expr_simplifier {
@@ -32,13 +32,9 @@ public:
     char const* name() const override { return "elim-term-ite"; }
         
     void reduce() override {
-        if (!m_fmls.has_quantifiers())
-            return;
         expr_ref r(m);
         for (unsigned idx : indices()) {
             auto const& d = m_fmls[idx];
-            if (!has_quantifiers(d.fml()))
-                continue;
             m_rewriter(d.fml(), r);
             m_fmls.update(idx, dependent_expr(m, r, d.dep()));
         }
diff --git a/src/ast/simplifiers/elim_unconstrained.cpp b/src/ast/simplifiers/elim_unconstrained.cpp
index d9fe5d480..713d7941c 100644
--- a/src/ast/simplifiers/elim_unconstrained.cpp
+++ b/src/ast/simplifiers/elim_unconstrained.cpp
@@ -130,6 +130,7 @@ void elim_unconstrained::init_nodes() {
     m_trail.append(terms);
     m_heap.reset();
     m_root.reset();
+    m_nodes.reset();
 
     // initialize nodes for terms in the original goal
     init_terms(terms);
@@ -159,6 +160,7 @@ void elim_unconstrained::init_terms(expr_ref_vector const& terms) {
         n.m_orig = e;
         n.m_term = e;
         n.m_refcount = 0;
+        
         if (is_uninterp_const(e))
             m_heap.insert(root(e));
         if (is_quantifier(e)) {
@@ -250,6 +252,8 @@ void elim_unconstrained::assert_normalized(vector<dependent_expr>& old_fmls) {
 void elim_unconstrained::update_model_trail(generic_model_converter& mc, vector<dependent_expr> const& old_fmls) {
     auto& trail = m_fmls.model_trail();
 
+    // fresh declarations are added first since 
+    // model reconstruction proceeds in reverse order of stack.
     for (auto const& entry : mc.entries()) {
         switch (entry.m_instruction) {
         case generic_model_converter::instruction::HIDE:
diff --git a/src/ast/simplifiers/flatten_clauses.h b/src/ast/simplifiers/flatten_clauses.h
index 02444f093..aa81024ef 100644
--- a/src/ast/simplifiers/flatten_clauses.h
+++ b/src/ast/simplifiers/flatten_clauses.h
@@ -28,7 +28,11 @@ class flatten_clauses : public dependent_expr_simplifier {
 
     bool is_literal(expr* a) {
         m.is_not(a, a);
-        return !is_app(a) || to_app(a)->get_num_args() == 0;        
+        if (m.is_eq(a) && !m.is_iff(a))
+            return true;
+        if (!is_app(a))
+            return true;
+        return to_app(a)->get_family_id() != m.get_basic_family_id();
     }
 
     bool is_reducible(expr* a, expr* b) {
@@ -49,14 +53,14 @@ public:
     }
         
     void reduce() override {
-        bool change = true;
-        
-        while (change) {
-            change = false;
+        unsigned nf = m_num_flat + 1;        
+        while (nf != m_num_flat) {
+            nf = m_num_flat;
             for (unsigned idx : indices()) {
                 auto de = m_fmls[idx];
                 expr* f = de.fml(), *a, *b, *c;
                 bool decomposed = false;
+                // (or a (not (or b_i)) => and_i (or a (not b_i))
                 if (m.is_or(f, a, b) && m.is_not(b, b) && m.is_or(b) && is_reducible(a, b)) 
                     decomposed = true;
                 else if (m.is_or(f, b, a) && m.is_not(b, b) && m.is_or(b) && is_reducible(a, b))
@@ -65,10 +69,10 @@ public:
                     for (expr* arg : *to_app(b)) 
                         m_fmls.add(dependent_expr(m, m.mk_or(a, mk_not(m, arg)), de.dep()));
                     m_fmls.update(idx, dependent_expr(m, m.mk_true(), nullptr));
-                    change = true;
                     ++m_num_flat;
                     continue;
                 }
+                // (or a (and b_i)) => and_i (or a b_i)
                 if (m.is_or(f, a, b) && m.is_and(b) && is_reducible(a, b))
                     decomposed = true;
                 else if (m.is_or(f, b, a) && m.is_and(b) && is_reducible(a, b))
@@ -77,7 +81,24 @@ public:
                     for (expr * arg : *to_app(b))
                         m_fmls.add(dependent_expr(m, m.mk_or(a, arg), de.dep()));
                     m_fmls.update(idx, dependent_expr(m, m.mk_true(), nullptr));
-                    change = true;
+                    ++m_num_flat;
+                    continue;
+                }
+                // not (and a (or b_i)) => and_i (not a) or (not b_i)
+                if (m.is_not(f, c) && m.is_and(c, a, b) && m.is_or(b) && is_reducible(a, b))
+                    decomposed = true;
+                else if (m.is_not(f, c) && m.is_and(c, b, a) && m.is_or(b) && is_reducible(a, b))
+                    decomposed = true;
+                if (decomposed) {
+                    expr* na = mk_not(m, a);
+                    for (expr* arg : *to_app(b))
+                        m_fmls.add(dependent_expr(m, m.mk_or(na, arg), de.dep()));
+                    m_fmls.update(idx, dependent_expr(m, m.mk_true(), nullptr));
+                    ++m_num_flat;
+                    continue;
+                }
+                if (m.is_implies(f, a, b)) {
+                    m_fmls.update(idx, dependent_expr(m, m.mk_or(mk_not(m, a), b), de.dep()));
                     ++m_num_flat;
                     continue;
                 }
@@ -85,7 +106,6 @@ public:
                     m_fmls.add(dependent_expr(m, m.mk_or(mk_not(m, a), b), de.dep()));
                     m_fmls.add(dependent_expr(m, m.mk_or(a, c), de.dep()));
                     m_fmls.update(idx, dependent_expr(m, m.mk_true(), nullptr));
-                    change = true;
                     ++m_num_flat;
                     continue;
                 }
diff --git a/src/ast/simplifiers/push_ite.h b/src/ast/simplifiers/push_ite.h
index e2acdbdb0..e26070a7e 100644
--- a/src/ast/simplifiers/push_ite.h
+++ b/src/ast/simplifiers/push_ite.h
@@ -38,7 +38,6 @@ public:
             m_fmls.update(idx, dependent_expr(m, r, d.dep()));
         }
     }
-
 };
 
 
diff --git a/src/sat/sat_solver/sat_smt_solver.cpp b/src/sat/sat_solver/sat_smt_solver.cpp
index c544df6fa..3fd3a0080 100644
--- a/src/sat/sat_solver/sat_smt_solver.cpp
+++ b/src/sat/sat_solver/sat_smt_solver.cpp
@@ -63,7 +63,7 @@ class sat_smt_solver : public solver {
         std::ostream& display(std::ostream& out) const override {
             unsigned i = 0;
             for (auto const& d : s.m_fmls) {
-                if (i == qhead())
+                if (i > 0 && i == qhead())
                     out << "---- head ---\n";
                 out << d << "\n";
                 ++i;